Optimization approachedfor improvement of mismic performances of steel buildings and members

点击翻译按钮获取中文摘要

1. The shape of the flanges of a cantilever beam has been optimized under monotonic and cyclic forced deflections, where the flanges and web are discretized to shell elements. The objective function to be maximized is the dissipated energy by plastic deformation, and the constraints are given for the plastic strain at the welded section. The locations of the control points of the B-spline curve are optimized by a heuristic approach called simulated annealing. This way the practically acceptable optimal shapes have been found by application of optimization techniques. The accuracy of finite element analysis has been verified by carryitig out by experimental study. The proposed framework of structural optimization can be applied to tuning up other structural parts such as gusset plates and stiffeners.2. Multiobjective optimization methods have been presented for steel frames under static and dynamic loading conditions. The cross-sectional properties of the members are selected from a pre … More defined list of available sections. It has been shown that many Pareto optimal solutions with enough diversity can be found by moderately small number of analysis by single-point-search heuristics such as simulated annealing and tabu search based on local march of feasible designs. This way, it has been shown that optimization techniques can be efficiently applied to problems with practical importance.3. In wide-flange steel column-to-beam connections, transverse stiffeners are often used to prevent local failure of columns caused by concentrated beam-flange force. The stiffeners work insufficiently if the beam-flange width is rather narrow relative to the column stiffening region. Loading tests using the beam-to-column connection models were conducted. The test results revealed an accuracy of the strength formula developed in the previous study. Measurements of the strain distribution and residual deformation of the test specimens confirmed validity of the failure mechanisms assumed in deriving the strength formula based on the yield line theory. Less